title: Effect of hematoporphyrin monomethyl ether-mediated photodynamic therapy on hypertrophic scar fibroblasts.
abstract: BACKGROUND
  Clinical studies have demonstrated that photodynamic therapy (PDT) for hyperplastic dermatosis results in a beneficial outcome. Hypertrophic scar (HS) is a pathological process characterized by fibroblastic hyperproliferation. However, it is unclear whether photochemical interactions between PDT and fibroblasts contribute to a beneficial outcome. To investigate the primary photochemical effects of PDT, we studied the efficacy of 630 nm PDT on human fibroblasts from HS using hematoporphyrin monomethyl ether (HMME) as a photosensitizer.
  
  
  METHODS
  Fibroblasts were cultured from nontreated HSs, and cells at passage 4-6 were used for the experiments. Morphological and biochemical changes in fibroblasts were assessed by Hoechst 33258 staining and annexin V-FITC/PI flow cytometry (FCM). Caspase-3 activity assay and immunofluorescence staining were performed to investigate caspase-3 expression in fibroblasts.
  
  
  RESULTS
  The morphological features of cell apoptosis were viewed under a fluorescent microscope by Hoechst 33258 staining. FCM indicated that the apoptotic rate was significantly increased after HMME-PDT, and caspase-3 activity was observed.
  
  
  CONCLUSIONS
  Low-level exposure to 630 nm PDT mediated by HMME appears to induce fibroblast apoptosis and stimulate caspase-3 activation. However, the effect of HMME-PDT on fibroblasts needs further investigation to determine its therapeutic potential for HS.
authors.affiliation: Department of Dermatology, Air Force General Hospital, Chinese PLA, Beijing, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Cai
authors.forename: Ying
authors.initials: Y
authors.lastname: Gu
authors.forename: Qiang
authors.initials: Q
authors.lastname: Sun
authors.forename: Jing
authors.initials: J
authors.lastname: Zeng
authors.forename: Ning
authors.initials: N
authors.lastname: Dong
authors.forename: Guang
authors.initials: G
authors.lastname: Zhao
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D002478:Cells, Cultured; D017439:Cicatrix, Hypertrophic / Q000188:drug therapy* / Q000473:pathology; D005347:Fibroblasts / Q000187:drug effects; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006415:Hematoporphyrins / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D008856:Microscopy, Fluorescence; D010778:Photochemotherapy
chemical_list: D006415:Hematoporphyrins; C494379:hematoporphyrin monomethyl ether